1. Field of the Invention
The invention relates to a connector with two housings and a bolt that generates forces to connect or disconnect the housings.
2. Description of the Related Art
Prior art connectors include first and second housings that can be connected to one another. Terminal fittings are mounted in each housing. The terminal fittings in the first housing are disposed to mate with the terminal fittings in the second housing when the housings are connected properly.
Connectors that are used in automotive vehicles often affect critical aspects of the vehicle operation. Performance of these important vehicular functions depends partly upon proper positioning of the terminal fittings in the housings. Proper positioning of the terminal fittings is complicated by the frequent vibration of the automotive vehicle and the broad range of temperature to which the vehicle may be exposed during normal use. Most connectors include locks to retain the terminal fittings in the housing. A common lock is formed unitarily with the housing and deflects as the terminal fitting is being inserted into the housing. The lock then returns resiliently to an undeflected condition when the terminal fitting is inserted properly and holds the terminal fitting in the housing. Other connectors include resiliently deflectable locks on the terminal fittings that engage a rigid structure on the housing.
Locks on the terminal fittings slide against the housing during insertion and produce frictional resistance forces that must be overcome to complete the terminal insertion. An operator could interpret these resistance forces as an indication of complete insertion and could stop the terminal insertion prematurely. An insufficiently inserted terminal fitting may not connect properly with a mating terminal fitting and could affect a critical circuit. As a result, most vehicle manufacturers require connectors to have terminal position assurance (TPA) members. A TPA member typically is formed separately from the housing and can be moved relative to the housing between a partial locking position and a full locking position. The TPA member can be moved to the full locking position if all of the terminal fittings have been inserted properly. However, an insufficiently inserted terminal fitting will interfere with the TPA member will impede the movement of the TPA member to the full locking position. Thus, an inability to move the TPA member to the full locking position any indicates that one or more terminal fittings have not been inserted properly.
Mating terminal fittings slide against one another during connection and create a friction resistance forces that must be overcome to connect the two housings of the connector properly. Similar resistance forces are generated during disconnection and must be overcome. The magnitude of the resistance forces is affected by the size and shape of the terminal fittings and the number of terminal fittings in each housing. Many prior art connectors include mechanical devices to facilitate connection and disconnection. The mechanical devices on some connectors include an internally threaded member in one housing and an externally threaded bolt in the mating housing. The bolt engages the internally threaded member during an early stage of mating. The bolt then can be rotated and the interengaged threads urge the housings and their terminal fittings into a full mated condition. Rotation of the bolt in the opposite direction separates the housings and the terminal fittings. The internally threaded member typically is a nut that is formed separately from the housing. Some nuts are secured in the housing by insert molding. Insert molding involves positioning the nut in the cavity of the mold that is used to form the housing. Resin then is injected into the housing and forms a unitary matrix that surrounds and supports exterior regions of the nut. Insert molded nut/housing assemblies perform well, but are very costly. Other nuts are press fit into the resin housing. More particularly, the nut has a knurled exterior surface that bites into the resin of the housing to hold the nut in place. Press fitting is much less costly than insert molding. However the press fit nut is positioned less securely and less precisely.